/*******************************************************************************
 * Copyright (c) 2005, 2014 springside.github.io
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 *******************************************************************************/
package org.whuims.service.task;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Sort;
import org.springframework.data.domain.Sort.Direction;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;
import org.springside.modules.persistence.DynamicSpecifications;
import org.springside.modules.persistence.SearchFilter;
import org.springside.modules.persistence.SearchFilter.Operator;
import org.whuims.entity.Task;
import org.whuims.repository.jpa.TaskDao;

import java.util.List;
import java.util.Map;

// Spring Bean的标识.
@Component
// 类中所有public函数都纳入事务管理的标识.
@Transactional
public class TaskService {

    private TaskDao taskDao;

    public Task getTask(Long id) {
        return taskDao.findOne(id);
    }

    public void saveTask(Task entity) {
        taskDao.save(entity);
    }

    public void deleteTask(Long id) {
        taskDao.delete(id);
    }

    public List<Task> getAllTask() {
        return (List<Task>) taskDao.findAll();
    }

    public Page<Task> getUserTask(Long userId, Map<String, Object> searchParams, int pageNumber, int pageSize,
                                  String sortType) {
        PageRequest pageRequest = buildPageRequest(pageNumber, pageSize, sortType);
        Specification<Task> spec = buildSpecification(userId, searchParams);

        return taskDao.findAll(spec, pageRequest);
    }

    /**
     * 创建分页请求.
     */
    private PageRequest buildPageRequest(int pageNumber, int pagzSize, String sortType) {
        Sort sort = null;
        if ("auto".equals(sortType)) {
            sort = new Sort(Direction.DESC, "id");
        } else if ("title".equals(sortType)) {
            sort = new Sort(Direction.ASC, "title");
        }

        return new PageRequest(pageNumber - 1, pagzSize, sort);
    }

    /**
     * 创建动态查询条件组合.
     */
    private Specification<Task> buildSpecification(Long userId, Map<String, Object> searchParams) {
        Map<String, SearchFilter> filters = SearchFilter.parse(searchParams);
        filters.put("user.id", new SearchFilter("user.id", Operator.EQ, userId));
        Specification<Task> spec = DynamicSpecifications.bySearchFilter(filters.values(), Task.class);
        return spec;
    }

    @Autowired
    public void setTaskDao(TaskDao taskDao) {
        this.taskDao = taskDao;
    }
}
